Detailed Instructions: In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.
Q: Question: Were more records sold overall by Summers' record company from the 1970s or the one she signed with in 1980? Passage:Having left Casablanca Records, with whom she had had some of the biggest selling and most popular hits of the disco era in the 1970s, Summer had signed to Geffen Records in 1980 and had continued working with Giorgio Moroder and Pete Bellotte, with whom she had written the vast majority of her hits. However, label owner David Geffen had been disappointed with the chart performance of the 1980 The Wanderer, Summer's debut album for Geffen and rather than release the followup; I'm a Rainbow which Summer had recorded with Moroder/Bellotte in 1981. Geffen had Summer record a new album with Quincy Jones from whom a production credit – given Jones' track record particularly his work with Michael Jackson – Geffen felt would guarantee a commercial smash. The resultant Donna Summer album was the first time the singer had worked with a producer other than Moroder and Bellotte since 1974 save for the one-off track "Down Deep Inside (Theme from "The Deep")" which was produced by John Barry for the film The Deep, and the "No More Tears (Enough is Enough)" duet with Barbra Streisand which was co-produced by Gary Klein of The Entertainment Company.
 Links: a. Casablanca Records b. John Barry (composer) c. Casablanca Records d. Disco
A:
a